Traditionally, roll formed products inherit their coatings from the raw material prior to the roll form manufacturing process. A continuous strip of steel, aluminum, vinyl, or paper is pretreated and pre-coated in a linear process prior to winding the strip into a coil on a mandrel. The final length of pretreated and pre-coated coil is removed from the mandrel to be shipped to a manufacturer that will uncoil the strip in a roll forming process, cutting the coil to length either just prior to the roll forming operation or cutting the roll formed product to length after the roll forming operation. In any regard, the final roll formed product is only coated as a result of its raw material coating prior to the roll forming process. Consequently, any cutting, punching, or piercing of the roll formed product may leave the substrate exposed, particularly along the cut edges.
Conventional pre-coating processes are complex, expensive, and often include the use of volatile organic compounds in both the cleaning of the raw material so contaminants do not interfere with the adhesion of the coating compound to the substrate raw material, but also in the application of the finished coating itself. Large industrial equipment including welders, accumulators and ovens are extremely expensive in terms of capital purchases, but also extremely expensive to operate. Typically, for such a process to be financially viable the user of this equipment must focus his/her business on the process of coating material processes. The cost of the processing adds to the cost of the original raw material substrate to which the coating is applied, consequently the cost is passed on to the manufacturer of the roll formed product, and ultimately, to the manufacturer's consumers.
It can be seen from the above, that the conventional method for coating roll formed products has many deficiencies. First, cut edges of roll formed products resulting from cutting operations during the roll forming process are left exposed, affecting the quality of weatherproofing or corrosion resistance characteristics of the substrate. Second, it requires a large amount of equipment and a building of substantial size to house the equipment and, thus, requires a significant investment of capital. Third, because of the factors and the many pieces of equipment involved in this process, the cost of operation and maintenance is significant. Fourth, the expense of operating the equipment and applying the coatings is passed on to the manufacturer who consumes the coated raw material for the purpose of creating the roll formed products in addition to profit margins from the raw material processor. Fifth, the large cost of coating the raw material limits the variations in coatings to what the supplied industry demands at a given price, while atypical variants in coatings come with a significant price increase applied to the purchaser due to the increased cost of running a “one-off” raw material coil. Lastly, it requires installation of pollution control equipment to minimize pollution to the atmosphere.